Apple (Malus domestica)

AntibioticsAntibiotics: In human research, proanthocyanidins, such as those found in apple juice, may inhibit bacterial adhesion in the urinary tract (76). Apple polyphenols (APP) showed no significant effect on the growth of the cariogenic bacteria in vitro and only scarcely inhibited enzyme activity, suggesting that APP might only selectively inhibit bacterial activity under oral conditions (77).

Antidiabetic agentsAntidiabetic agents: In human research, the fiber in apple may help regulate type 2 non-insulin-dependent diabetes (78) and consumption of whole apple reduced plasma glucose (29). However, in other human studies, consumption of apple resulted in a marked increase in blood sugar and insulin (30; 31). Apple fiber does not appear to attenuate carbohydrate absorption in humans (79; 28; 2), and apple pectin has shown a scavenger effect in intestinal digestion (80).

Antilipemic agentsAntilipemic agents: In humans, apple juice used to deliver the fiber supplement in one study may have contributed to the increase in total mean cholesterol and triglyceride concentrations (18). Similarly, apple powder increased low-density lipoprotein (LDL) and total cholesterol levels in patients with diabetes (36). However, in a separate study, the fiber from apples and gum arabic has been shown to lower total and low-density lipoprotein cholesterol levels in men with mild hypercholesterolemia (81).

Antiplatelet and anticoagulant agentsAntiplatelet and anticoagulant agents: Concurrent use of apples and anticoagulants and antiplatelet agents may theoretically increase the risk of bleeding, based on the mechanism of action of constituent flavonoids. Although flavonoid compounds in fruits and vegetables are thought to have cardioprotective effects, patients given apple, vegetables, and berries for six weeks in one study did not differ in platelet counts or levels of inflammation (82).

Calcium saltsCalcium salts: Fruit consumption has been shown to reduce net acid excretion (NAE) and urinary calcium excretion; compared to baseline, NAE increased after control treatment but decreased after fresh or processed apple treatment (p=0.041) (83). Calcium excretion increased with all treatments, but the increase was the least for fresh apple and applesauce (p=0.024).

CisplatinCisplatin: In humans, administration of cisplatin alone or in combination with other cytotoxic agents commonly produces intractable nausea and vomiting, which may be treatable with food, including applesauce (84).

FexofenadineFexofenadine: In humans, apple juice was found to decrease the fexofenadine area under the plasma concentration time curve, the peak plasma drug concentration, and the urinary excretion values, with no effect on time to reach C(max), elimination half-life, renal clearance, or urine volume; this effect was found to occur by inhibiting organic anion transporting polypeptides (OATP) (38).

Iron saltsIron salts: Iron absorption was enhanced when ingested with apple juice (2). Other studies have reported a lack of effect on iron absorption when administered with apple juice (86; 87).

AntibacterialsAntibacterials: In human research, proanthocyanidins, such as those found in apple juice, may inhibit bacterial adhesion in the urinary tract (76). Apple polyphenols (APP) showed no significant effect on the growth of the cariogenic bacteria in vitro and only scarcely inhibited enzyme activity, suggesting that APP might only selectively inhibit bacterial activity under oral conditions (77).

AntilipemicsAntilipemics: In humans, apple juice used to deliver the fiber supplement in one study may have contributed to the increase in total mean cholesterol and triglyceride concentrations (18). Similarly, apple powder increased low-density lipoprotein (LDL) and total cholesterol levels in patients with diabetes (36). However, in a separate study, the fiber from apples and gum arabic has been shown to lower total and low-density lipoprotein cholesterol levels in men with mild hypercholesterolemia (81).

Antiplatelet and anticoagulant agentsAntiplatelet and anticoagulant agents: Concurrent use of apples and anticoagulants and antiplatelet agents may theoretically increase the risk of bleeding, based on the mechanism of action of constituent flavonoids. Although flavonoid compounds in fruits and vegetables are thought to have cardioprotective effects, patients given apple, vegetables, and berries for six weeks in one study did not differ in platelet counts or levels of inflammation (82).

CalciumCalcium: Fruit consumption has been shown to reduce net acid excretion (NAE) and urinary calcium excretion; compared to baseline, NAE increased after control treatment but decreased after fresh or processed apple treatment (p=0.041) (83). Calcium excretion increased with all treatments, but the increase was the least for fresh apple and applesauce (p=0.024).

FiberFiber: Apple is a source of dietary fiber. Concurrent use with other sources of dietary fiber theoretically may have additive effects.

HypoglycemicsHypoglycemics: In human research, the fiber in apple may help regulate type 2 non-insulin-dependent diabetes (78) and consumption of whole apple reduced plasma glucose (29). However, in other human studies, consumption of apple resulted in a marked increase in blood sugar and insulin (30; 31). Apple fiber does not appear to attenuate carbohydrate absorption in humans (79; 28; 2), and apple pectin has shown a scavenger effect in intestinal digestion (80).

IronIron: Iron absorption was enhanced when ingested with apple juice (2). Other studies have reported a lack of effect on iron absorption when administered with apple juice (86; 87).

QuercetinQuercetin: Urinary excretion of quercetin, a constituent in apple, increased significantly with dose and time after participants ingested blackcurrant and apple juice (1:1 ratio) in 150, 1,000, and 1,500mL strengths for one week (corresponding to an intake of 4.8, 6.4, and 9.6mg of quercetin daily) (92).

Vitamin EVitamin E: Apple pectin plus vitamin E (RRR-alpha-tocopheryl acetate, all-rac-alpha-tocopheryl acetate, RRR-alpha-tocopherol, RRR-alpha-tocopheryl succinate, and RRR-alpha-tocopheryl acetate) were given to 20 adult subjects in an attempt to determine the biological activity of vitamin E compounds in humans, which may have been underestimated in the previously studied rat model (93). Further details are not available at this time.

Blood glucose and insulinBlood glucose and insulin: In human research, the fiber in apple may help regulate type 2 non-insulin-dependent diabetes (78) and consumption of whole apple reduced plasma glucose (29). However, in other human studies, consumption of apple resulted in a marked increase in blood sugar and insulin (30; 31).

Gastric pHGastric pH: The results of studies of the effects of apple juice, particularly before surgery, on gastric contents and acidity are conflicting. Studies in adults found that apple juice consumption before surgery led to an increase in gastric contents and possibly caused aspiration pneumonia (9; 24). However, in other research, apple juice prior to elective surgery did not worsen gastric volume or acidity (69). Apple juice served as an acceptable substitute for extended pH monitoring in an outpatient gastroesophageal reflux evaluation (94).

Lipid profileLipid profile: In humans, apple juice used to deliver the fiber supplement in one study may have contributed to the increase in total mean cholesterol and triglyceride concentrations (18). Similarly, apple powder increased low-density lipoprotein (LDL) and total cholesterol levels in patients with diabetes (36). However, in a separate study, the fiber from apples and gum arabic has been shown to lower total and low-density lipoprotein cholesterol levels in men with mild hypercholesterolemia (81).

Prostaglandin E2Prostaglandin E2: In rats, administration of 20% of pectin from apple, instead of a basal diet, produced lower prostaglandin E2 in the distal colonic mucosa and blood of portal vein (80).

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.